Arrangement adapted to generate ultra short electromagnetic waves



Feb, H936.

ARRANGEMENT E. FETTEROWSKY ET AL. ZEELEH ADAPTED 'I 0 GENERATE ULTRASHORT ELECTROMAGNETIC WAVES Filed July 1, 1933 MODULAWA/G DEV/C6Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE ARRANGEMENT ADAPTEDTO GENER- ATE ULTRA SHORT ELECTROMAGNETIC WAVES Application July 1,1933, Serial No. 678,570 In Germany July 13, 1932 2 Claims.

For the generation of extra short electroma netic waves, recourse may behad, as known from the earlier art, to the socalled Barkhausen-Kurzcircuit which has this distinguishing feature, that 5 the control gridin a tube with three or more electrodes is supplied with a high positivevoltage and the plate with a negative voltage. The present inventiondiscloses a circuit scheme in which the outer plate potential source maybe dispensed with.

The plate current in a Barkhausen-Kurz circuit arrangement containing anoscillating tube is due to that part of the electrons which are emittedfrom the cathode and accelerated by the positive grid potential and flyagainst and strike the negatively biased plate. The sense of the currentthus is such that the current flows into the plate battery and tends tocharge the same. The incidental consumption of energy is covered by thegrid battery. Now, according to the invention, the negative potentialrequired at the plate could be produced simply by connecting the latterwith the cathode by way of a suitably chosen resistance R as illustratedin Figure 1. The sense of the plate current is such that the end of theresistance united with the plate, in ref erence to the filament, is ofnegative potential.

Figures 1 and 2 illustrate two difierent embodiments of the invention.

Referring to Figure 1, for the adjustment of the proper potential, thesaid resistance R is preferably made adjustable. The resistance acts atthe same time also as a radio frequency choke and it prevents or impedesthe drain of oscillations into the battery wires. However, if a distinctchoke coil Dr is to be used, then it is advisable to arrange a condenserC in parallel relation to the resistance R to act as an energyaccumulator.

As shown in Figure 2, the variable resistance could consist also of thefilament plate path of a triode M in which case variation of resistanceis insured by variation of the grid biasing voltage Eg. The samearrangement, unaltered, could be employed also for the modulation of theradio frequency oscillation by audio frequency impulses which are fed tothe grid of the input tube M, say, by way of a transformer T. The use ofan input tube in the plate D. C. circuit for modulation of theoscillations as known in the prior art could in the present case bedeveloped in that the tube serves at the same time for the production ofthe negative plate potential.

What is claimed is:

1. An ultra short wave circuit comprising an electron discharge devicehaving anode, cathode and control electrodes, a source of potential incircuit with said cathode and control electrode for applying to saidcontrol electrode a high positive potential with respect to cathode, andmeans excluding the use of a separate source of anode potential forcausing said anode mice at a negative potential with respect to saidcathode, said last means comprising an efiective resistance connectedbetween said anode and cathode which is arranged to be traversed by thecurrent in said anode circuit.

2. A system in accordance with claim 1 including a condenser in shuntwith said efiective resistance and a choke coil serially arranged incircuit with said resistance between said anode and cathode.

EDUARD FETTEROWSKY. HEINZ LUX.

